popsu-d7/sites/all/modules/twitter/twitter_signin/twitter_signin.module

<?php

/**
 * Implements hook_menu().
 */
function twitter_signin_menu() {
  $items['twitter/redirect'] = array(
    'title' => 'Twitter Redirect',
    'page callback' => 'twitter_signin_redirect',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );

  $items['admin/config/services/twitter/signin'] = array(
    'title' => 'Sign-in',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('twitter_signin_admin_settings'),
    'access arguments' => array('administer site configuration'),
    'file' => 'twitter_signin.pages.inc',
    'type' => MENU_LOCAL_TASK,
    'weight' => 5,
  );

  return $items;
}

/**
 * Implements hook_block_info().
 */
function twitter_signin_block_info() {
  $block[0]['info'] = t('Sign in with Twitter');
  return $block;
}

/**
 * Implements hook_block_view().
 */
function twitter_signin_block_view($delta) {
  global $user;

  if (!$user->uid && _twitter_use_oauth()) {
    $block['subject'] = t('Sign in with Twitter');
    $block['content'] = twitter_signin_button();
    return $block;
  }
}

/**
 * returns an image link for signing in with twitter
 */
function twitter_signin_button() {
  $img = drupal_get_path('module', 'twitter_signin') . '/images/' . variable_get('twitter_signin_button', 'Sign-in-with-Twitter-lighter-small.png');

  return l(theme('image', array('path' => $img, 'alt' => t('Sign in with Twitter'))), 'twitter/redirect', array('html' => TRUE));
}

/**
 * Submit handler for twitter signin
 */
function twitter_signin_redirect() {
  module_load_include('lib.php', 'oauth');
  module_load_include('lib.php', 'twitter');
  module_load_include('inc', 'twitter');

  $key = variable_get('twitter_consumer_key', '');
  $secret = variable_get('twitter_consumer_secret', '');
  $twitter = new TwitterOAuth($key, $secret);
  $token = $twitter->get_request_token();

  $_SESSION['twitter_oauth']['token'] = $token;
  $_SESSION['twitter_oauth']['destination'] = $_SERVER['HTTP_REFERER'];
  $_SESSION['twitter_oauth']['signin'] = TRUE;
  drupal_goto($twitter->get_authenticate_url($token));
}

/**
 * Implements hook_form_alter().
 */
function twitter_signin_form_alter(&$form, $form_state, $form_id) {
  // This only applies if we've got OAuth / signin enabled.
  if (!_twitter_use_oauth()) {
    return;
  }

  if ($form_id == 'twitter_oauth_callback_form' && isset($_SESSION['twitter_oauth']['signin'])) {
    $form['#submit'] = array_merge(array('twitter_signin_oauth_callback_submit'), $form['#submit']);
  }

  if ($form_id == 'user_login' || $form_id == 'user_login_block') {
    $items = array();
    $items[] = twitter_signin_button();

    $form['twitter_signin'] = array(
      '#markup' => theme('item_list', array('items' => $items)),
    );
  }
  elseif ($form_id == 'user_register_form' && isset($_SESSION['twitter']['values'])) {
    $form['account']['name']['#default_value'] = $_SESSION['twitter']['values']['screen_name'];
    $form['auth_twitter'] = array(
      '#type' => 'hidden',
      '#value' => $_SESSION['twitter']['values']['user_id'],
    );
  }
}

/**
 * Form submit for the OAuth callback. Here we add in sign-in specific handling
 */
function twitter_signin_oauth_callback_submit(&$form, &$form_state) {
  global $user;

  $success = FALSE;

  $key = variable_get('twitter_consumer_key', '');
  $secret = variable_get('twitter_consumer_secret', '');
  $response = $form_state['twitter_oauth']['response'];

  $account = user_external_load($response['user_id']);
  if (isset($account->uid)) {
    user_external_login($account, $response);
    $success = TRUE;
  }
  elseif ($uid = db_query("SELECT uid FROM {twitter_account} WHERE twitter_uid = :twitter_uid", array(':twitter_uid' => $response['user_id']))->fetchField()) {
    // We have an existing twitter account - set it up for login
    $account = user_load($uid);
    $edit["authname_twitter"] = $response['user_id'];
    user_save($account, $edit);
    $user = $account;
    $form_state['twitter_oauth']['account'] = $account;
    $success = TRUE;
  }
  else {
    // No existing user account, let's see if we can register.
    if (variable_get('twitter_signin_register', 0)) {
      // Check for a nickname collision
      $account = array_shift(user_load_multiple(array(), array('name' => $response['screen_name'])));
      if (empty($account->uid)) {
        $edit = array(
          'name' => $response['screen_name'],
          'pass' => user_password(),
          'init' => $response['screen_name'],
          'status' => 1,
          "authname_twitter" => $response['user_id'],
          'access' => REQUEST_TIME,
        );
        $account = user_save('', $edit);
        $user = $account;
        $form_state['twitter_oauth']['account'] = $account;
        $success = TRUE;
      }
      else {
        drupal_set_message(t('The nickname %name is already in use on this site, please register below with a new nick name, or @login to continue.', array('%name' => $response['screen_name'], '@login' => url('user/login'))), 'warning');
      }
    }
    else {
      drupal_set_message(t('Please log in or register to relate your Twitter account with a user.'));
    }
  }

  if (!$success) {
    $_SESSION['twitter']['values'] = $response;
    drupal_goto('user/register');
  }
}

/**
 * Implements hook_user_insert()
 *
 * Relates a Twitter account with a just created user account if the user
 * signed in with Twitter but did not have an account in the site yet
 */
function twitter_signin_user_insert(&$edit, $account, $category) {
  _twitter_signin_add_account($account);
}

/**
 * Implements hook_user_insert()
 * 
 * Relates a Twitter account with an existing user account if the user
 * signed in with Twitter
 */
function twitter_signin_user_login(&$edit, $account) {
  _twitter_signin_add_account($account);
}

/**
 * Relates a user account with a twitter account
 *
 * @param $account
 * The Drupal user account
 */
function _twitter_signin_add_account($account) {
  if (isset($_SESSION['twitter']['values'])) {
    module_load_include('lib.php', 'twitter');
    module_load_include('inc', 'twitter');
    $key = variable_get('twitter_consumer_key', '');
    $secret = variable_get('twitter_consumer_secret', '');
    $response = $_SESSION['twitter']['values'];

    $twitter = new TwitterOAuth($key, $secret, $response['oauth_token'], $response['oauth_token_secret']);
    $twitter_account = $twitter->users_show($response['screen_name']);
    $twitter_account->set_auth($response);
    twitter_account_save($twitter_account, TRUE, $account);

    unset($_SESSION['twitter']);

    drupal_set_message(t('You have related a Twitter account with your user. Next time you can sign in with Twitter.'));
  }
}